Juvenile Huntington's disease: two case reports and a review of the literature

Huntington's disease is a rare, autosomal dominant neurodegenerative disease characterized by motor, cognitive, and psychiatric symptoms. Usually, the disease symptoms first appear around the age of 40, but in 5-10% of cases, they manifest before the age of 21. This is then referred to as juvenile Huntington's disease. According to the small number of cases reported in the literature, the course of juvenile Huntington's disease significantly differs from adult onset and shows significant interpatient variability, making every case unique.

Our study aims to highlight the complexity and diversity of rare juvenile Huntington's disease. We report cases of two Caucasian patients with chronic tics referred to the Huntington's Disease Competence Center of Vilnius University Hospital Santaros Klinikos with suspicion of juvenile Huntington's disease due to the appearance of chronic motor tics, and behavior problems. The diagnosis of juvenile Huntington's disease was confirmed on both clinical and genetic grounds. In both cases described, the patients developed symptoms in all three main groups: motor, cognitive, and psychiatric. However, the first patient was experiencing more severe psychiatric symptoms; in the second case, motor symptoms (rigidity, tremor) were more prominent. In both cases, apathy was one of the first symptoms and affected patients' motivation to participate in treatment actively. These two case descriptions serve as an important message for clinicians seeing patients with chronic tics and gradually worsening mood and behavior, indicating the need to investigate them for rare genetic disorders.

Description of these two clinical cases of juvenile Huntington's disease provides insight into how differently it manifests and progresses in young patients and the difficulties the patients and their families face. There were different but painful ways for families to accept the diagnosis. Because the disease inevitably affects the patient's closest ones, it is crucial to also provide adequate psychological and social support to all the family members. Establishment of multidisciplinary specialist centers for Huntington's disease, as demonstrated by our experience, not only allows timely diagnosis and treatment plans but also ensures thorough disease management and care for patients and systematic support for their families.